In the process of thermal printing, it is desirable to fuse the printed image to enhance optical properties and to make the image more permanent. There are several methods of fusing. One method of fusing utilizes a dye donor web to impart the color image to a receiver media, and has a clear fuser patch incorporated in the web. After the yellow, magenta and cyan colors are thermally transferred to the receiver media, the clear fuser patch fuses the color image. One of the drawbacks of using a dye donor with a clear fuser patch incorporated therein is the increased probability of artifacts occurring in the finished thermal print.
Another method of fusing utilizes a separate fuser mechanism. The receiver media with the color image thereon is passed between heated rollers in the fuser mechanism. In a mechanism of this sort, a fuser web separate from the dye donor web is provided for the fusing so that it overlays the printed image. Such a system is satisfactory for prints with borders, but creates a problem when the print is borderless. With a borderless print to ensure complete coverage of the image area. Because the fuser web is wider, portions of the fuser web overhang the receiver media, and, when the heating is done, the fuser web contacts the fuser roller. In this process, debris or residue is left on the fuser roller which not only clogs the fuser mechanisms but creates artifacts or other imperfections in the borderless print as well.
Obviously, if the fuser web were properly sized to be exactly as wide as the borderless print, there would be no problem with build-up on the fuser roller or the heating element. As a practical matter, however, it is cost prohibitive to have the fuser web exactly the same size as the borderless print for at least two reasons. First, even when they are designed to be the same size, they are only the same size within certain tolerances, the closer the tolerances the more expensive. Second, because printers typically utilize different sizes of receiver web, it is more efficient to have a one-size-fits-all fuser web to minimize supplies needed to be stocked and to eliminate time required to change fuser webs for different sizes. Accordingly, it will be appreciated that it would be highly desirable to have a fuser mechanism wherein the fuser web is a single width for all widths of receiver media, but does not contribute to residue deposit on the roller or the heating element.